Arid Zone Research ›› 2022, Vol. 39 ›› Issue (1): 282-291.doi: 10.13866/j.azr.2022.01.27

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Spatial-temporal evolution of wetland landscape patterns and its influencing factors in the middle reaches of the Shule River

WANG Yufang(),ZHAO Chengzhang(),ZENG Hongxia,KANG Manping,ZHAO Tingting,TANG Yurui   

  1. College of Geography and Environmental Science, Northwest Normal University, Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province, Lanzhou 730070, Gansu, China
  • Received:2021-01-18 Revised:2021-03-15 Online:2022-01-15 Published:2022-01-24
  • Contact: Chengzhang ZHAO E-mail:1481977435@qq.com;zhaocz601@163.com

Abstract:

Wetland landscape patterns can reflect the area variations and the spatial distribution characteristics of wetland types; and their spatio-temporal evolution assists in understanding the relationship between disturbance factors and wetland ecological processes. In this paper, five wetland types—including reservoir wetland, permanent river wetland, and inland salt marsh—were selected for analysis in the middle reaches of the Shule River in China. Landscape pattern, correlation, and principal component analysis were used to study the area of these wetland types, the spatio-temporal evolution of the landscape index and its influencing factors. The results show that: (1) In the past 30 years, the total area of wetlands in the middle reaches of the Shule River decreased by 477.24 km2. Among the wetland types, reservoir wetlands, permanent river wetlands, and inland salt marshes decreased by 50.99%, 53.28%, and 35.78%, respectively, whereas the herb marsh and swamp meadow areas increased by 175.26% and 21.89%, respectively. (2) At the landscape and class levels, the patch density and landscape shape index of each wetland type showed a trend of fluctuation and increase, and the patch density of the wetland landscape tended to be fragmented and scattered. (3) In 2017, the population and cultivated land experienced a 1.2-fold and 1.5-fold increase, respectively, compared with 1987. The interpretation degree of the main indicators of social and economic development on wetland area change was 68.69%, and that of climatic factors was 22.09%. Population growth, farmland expansion, and water conservancy projects over the past 30 years led to the reduction of wetland areas and landscape fragmentation in the middle reaches of the Shule River.

Key words: wetland, landscape pattern, influencing factors, principal component analysis, middle reaches of the Shule River